That, who, or which

I have a twofold career: as well as writing blogs about grammar and usage, I also teach English as a foreign language. Explaining the more arcane and sometimes illogical nuances of English grammar to native and non-native speakers alike can be challenging, but I relish the chance to do so. I’ve found that some people switch off at the first mention of grammar, while others are happy with the basics of nouns, adjectives, and verbs, but their eyes glaze over the minute I delve into topics such as transitivity or submodifiers.

Let’s address a recent query posted on this blog:

‘People often say that when referring to others when I believe they should say who or whom, e.g. “there’s somebody over there that I know”. Is this correct? […] it seems to happen all the time.’

This is an excellent topic for me to explore: it raises an important difference between the use of that and who as relative pronouns. I also thought it would also be useful to discuss relative clauses and the use of ‘which’ versus ‘that’, where there’s a divergence between British and US English. As to the difference between who and whom, I’ll leave that for another blog (if you’re interested, here’s a quick and useful explanation).

Human or not?

First things first: who, that, and which can all function as relative pronouns in a sentence or clause. This means that they are used to refer back to a person or thing that was previously mentioned. One of the distinctions between that, which, and whoas relative pronouns is based on whether you’re talking about people or things. Take a look at the following examples:

They’re just a normal couple and their kids are everyday kids [people/person] who [relative pronoun] play in the street.

You must have your own work area [thing] which [relative pronoun] can be cut off from the rest of the house.

I love the watch [thing] that [relative pronoun] you gave me for my birthday.

So that and which are the relative pronouns that we use to talk about things. The main difference between who and that or which is that you should only use who to refer to a person or people – who is never used to refer to things. This rule also applies to organizations, but it’s a common mistake to use whoin such contexts:

√Firefighters had to help a manwho was trapped in the car.

X There are a lot of charities who need good advice.

√There are a lot of charities which need good advice.

Conversely, is it OK to use which or that as a relative pronoun to refer to a person? In the past, which was often used in this way. If you were brought up in the Anglican Church, as I was, you might be familiar with the wording of the Lord’s Prayer as it appears in the 1662 edition of the Book of Common Prayer:

Our Father, which art in heaven…

When I recited the prayer as a child in the 1960s, I often wanted to say ‘who’ rather than ‘which’ – it seemed more natural to use who because we were talking about a person [Father], not a thing. In fact, had our parish priest used the 1928 edition of the Book of Common Prayer, I would have encountered the more recent wording:

Our Father, who art in heaven….

This neatly illustrates the point that until the 19th century, it was part of normal English to use which as a relative pronoun to refer to a person or people, but nowadays it has an archaic or even incorrect feel. Contemporary grammarians advise explicitly against it:

X I called a taxidriver, whichagreed to meet us near the petrol station.

To return to that, some authorities have argued that, in relative clauses, thatshould only be used for non-human references:

√ This is not a car that should be recommended for families.

? She’s the woman thatlivesnext door.

In fact, people have been using that for human and non-human references since at least the 11th century, and thatis handy if you want to talk about both a person and a thing:

√ A jinx is a person or thing that is believed to bring bad luck.

√ It was the drug and not her brother that had upset her.

or if you’re just referring to a person in an unspecific way:

Most of the people that come to these classes are overweight.

You seem to be very judgemental of anyone that’s older than you.

They hired someone that could be a focal point for all these calls from the media.

That or which?

So now we’ve answered the question ‘Do I use who, that, or which?’ let’s move on to the main distinction between that and which, where there’s a difference between British and American English. In British English, if a clause contains essential information about the noun that comes before it, it’s acceptable to choose that or which:

√She wore the dress which suited her best.

√She wore the dress that suited her best.

In these sentences, that and which are introducing what’s called a restrictive relative clause. If you leave out this type of clause, the meaning of the sentence is affected – in most cases, it won’t make much sense at all:

? She wore the dress.

However, in US English, most authorities and guides recommend that you use that rather than which to introduce a restrictive relative clause:

√She wore the dress that suited her best.

X She wore the dress which suited her best.

The other type of relative clause is a non-restrictive relative clause. This kind of clause contains extra information that could be left out of the sentence without affecting the meaning or structure:

My new dress, which is made of linen [non-restrictive relative clause], looks great with my blue sandals.

My new dress looks great with my blue sandals.

You’ll be relieved to learn that both US and British English are singing from the same hymn sheet here: both varieties of English agree that you should never use that to introduce a non-restrictive relative clause:

√ The horse, which she bought last year, is six years old.

X The horse, that she bought last year, is six years old.

I hope you’ve also spotted that you should use a comma before and (if the clause is in the middle of a sentence) after non-restrictive clauses, so as to mark off the extra and inessential information. It’s incorrect (but a very common error) to use a comma with a restrictive relative clause:

X She wore the dress, that suited her best.

By the way, although we’re focusing on that and which here, both types of relative clause can also be introduced by whose, who, or whom in British and US English, and the same rules apply with regard to the use of commas:

√My father, who lives in New York [non-restrictive relative clause], is 82 this year.

The facts at a glance

To sum up, here’s a handy table which shows the dos and don’ts:

Relative pronoun

Relative clause referring to person or people

Relative clause referring to things

Restrictive relative clause [British English]

Restrictive relative clause [US English]

Non-restrictive relative clause [British English]

Non-restrictive relative clause [US English]

that

√

√

√

√

X

X

which

X [only found in old-fashioned texts]

√

√

X

√

√

who

√

X

√

√

√

√

The opinions and other information contained in OxfordWords blog posts and comments do not necessarily reflect the opinions or positions of Oxford University Press.

Comments

Thank you so much for this post. I never had grammar in school, and I’m loving the intricacies of it now. Fortunately, I have a good “ear” for what is right, but now I’m learning the why and figuring out my grey areas … and impressing (and boring) my friends with impressive sounding terms like non-restrictive relative clauses. I’ve lived in both the US and UK, and it is nice to know I wasn’t going insane that certain things just sounded “wrong” or at least different from what I was used to hearing.

Art

Hello, writer. This is very useful for me.
So let me introduce myself.
I’m Thai and a student in grade 12.
Anyway, I just would like to ask you.
How can I use “in which, by which, on which, or something like those?
Sorry for my English grammar if there is something incorrect.
Thank you.